1. Field of the Invention
The present invention relates to a mixer for a liquid chromatograph and, in particular, to a mixer which is used to mix liquids together so as to make an eluent for gradient analysis.
2. Description of the Related Art
In a liquid chromatograph, there is made a gradient analysis in which the composition of an eluent is caused to vary continuously or in a stepped manner. In the gradient analysis, in order that two or more kinds of liquids are mixed together to thereby introduce a column as an eluent, a gradient eluting apparatus includes a mixer for mixing a plurality of liquids together. As the mixer, there is often used an apparatus of a flow-through type which does not include a movable part; for example, there is known an apparatus structured such that balls made of stainless steel are loaded into a pipe having an inside diameter of about 3 mm and a length of about 50 mm. This type of mixer is composed of a plurality of machined parts such as entrance and exit machined parts. In the case of such mixer, since balls for mixing are loaded into the interior of the mixer, the internal capacity thereof is large. In order to mix together the plurality of liquids with high efficiency, there is required the optimum mixer capacity according to the flow quantities of the liquids; however, a flow passage for such mixture depends on the balls loaded into the interior of the pipe, which makes it impossible to form a desired flow passage. In addition, this type of mixer is complicated in machining and assembling, which results in the high cost thereof.